U.S. patent number 5,935,057 [Application Number 09/058,674] was granted by the patent office on 1999-08-10 for device for carrying two units in end to end disposition and for moving one of the units alongside the other of the units.
This patent grant is currently assigned to Vista Medical Technologies, Inc.. Invention is credited to Koichiro Hori, Philip R. Lichtman.
United States Patent |
5,935,057 |
Lichtman , et al. |
August 10, 1999 |
**Please see images for:
( Certificate of Correction ) ** |
Device for carrying two units in end to end disposition and for
moving one of the units alongside the other of the units
Abstract
A device carries first and second units in aligned end-to-end
disposition at a distal end of a shaft and provides structure for
moving the second of the units into position alongside the first of
the units. The device comprises a base portion to which a proximal
end of the shaft is fixed, the first unit being fixed to a distal
end of the shaft. A rod extends lengthwise through the shaft and a
portion of the first unit, and is off-set from an axis of the shaft
and fixed to the second unit removed from an axis of the second
unit. Mounted on the base portion is an operating mechanism for
effecting rotational movement of the rod to effect rotational
movement of the second unit to a position removed from alignment
with the first unit, and for effecting axial movement of the rod to
effect axial movement of the second unit into the position
alongside the first unit, said operating mechanism comprising a
gear clutch mechanism for shifting movement of said rod from a
rotational mode to an axial translational mode, and back again to
said rotational mode.
Inventors: |
Lichtman; Philip R. (Newton,
MA), Hori; Koichiro (Framingham, MA) |
Assignee: |
Vista Medical Technologies,
Inc. (Carlsbad, CA)
|
Family
ID: |
24518926 |
Appl.
No.: |
09/058,674 |
Filed: |
April 10, 1998 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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628448 |
Apr 5, 1996 |
5782752 |
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Current U.S.
Class: |
600/137; 600/129;
600/173; 74/22A |
Current CPC
Class: |
A61B
1/0052 (20130101); A61B 5/1076 (20130101); Y10T
74/18808 (20150115); A61B 1/00193 (20130101); Y10T
74/18032 (20150115) |
Current International
Class: |
A61B
1/005 (20060101); A61B 5/107 (20060101); A61B
1/00 (20060101); A61B 001/05 (); F16H 021/50 () |
Field of
Search: |
;600/101,106,109,112,129,137,166,173
;74/89.17,89.13,89.15,22R,22A |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Leubecker; John P.
Attorney, Agent or Firm: Pandiscio & Pandiscio
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of patent application Ser. No.
08/628,448, filed Apr. 5, 1996, in the name of Philip R. Lichtman
now U.S. Pat. No. 5,782,752.
Claims
Having thus described my invention, what we claim as new and desire
to secure by Letters Patent of the United States is:
1. A device for carrying first and second units in aligned
end-to-end disposition at a distal end of a shaft and for moving
said second unit into a predetermined position alongside said first
unit, said device comprising:
a shaft having proximal and distal ends; first and second units
adapted to be aligned in end-to-end disposition; a base portion to
which the proximal end of said shaft is fixed, said first unit
being fixed to the distal end of said shaft in alignment with said
shaft;
a rod extending lengthwise through said shaft and through a portion
of said first unit, said rod being off-set from an axis of said
shaft and being fixed at a distal end thereof to said second unit
at a location removed from an axis of said second unit;
a drive shaft fixed to said rod at a proximal end of said rod, said
drive shaft having a threaded portion and a non-threaded portion;
and
an operating mechanism mounted on said base portion for
sequentially (a) effecting rotational movement of said drive shaft
to effect rotational movement of said rod in a direction to thereby
rotate said second unit from said aligned end-to-end disposition to
a position removed from alignment with said first unit, and (b)
effecting axial movement of said drive shaft and said rod in a
direction to move said second unit into said predetermined position
alongside said first unit, said operating mechanism comprising a
gear friction clutch that is engaged when said first and second
units are in end-to-end disposition and disengaged while said drive
shaft and said rod are being rotated and undergoing axial
movement.
2. The device according to claim 1 wherein said gear friction
clutch comprises a gear nut screwed onto said threaded portion of
said drive shaft and adapted for frictionally clutching said
non-threaded portion of said shaft when said nut is rotated in a
predetermined direction relative to said shaft, and drive means
mounted to said base portion for rotating said gear nut.
3. The device according to claim 2 wherein said drive means
includes a drive gear that is engaged with said gear nut so that
rotation of said drive gear will cause rotation of said gear
nut.
4. The device in accordance with claim 3 wherein said drive gear is
mounted on an actuating shaft having grip means for manual turning
said actuating shaft.
5. The device in accordance with claim 3 wherein said drive gear is
mounted on the output shaft of a reversible electrical motor,
whereby energization of said motor will cause said drive gear to
rotate said gear nut.
6. The device in accordance with claim 2 wherein said gear nut is
restrained against movement lengthwise of said drive shaft.
7. The device in accordance with claim 6 wherein said gear nut has
a circumferentially-extending peripheral groove, and further
including means attached to said base portion and extending into
said groove for restraining said gear nut against movement
lengthwise of said drive shaft.
8. The device in accordance with claim 6 wherein said gear nut has
an internal conically shaped clutch surface and said non-threaded
portion of said drive shaft has an external conically shaped clutch
surface adapted to make a friction tight engagement with said
internal conically shaped clutch surface when said gear nut is
rotated in a first direction relative to said drive shaft, whereby
further rotational movement of said gear nut will result in
rotational movement of said drive shaft in the same direction.
9. The device in accordance with claim 1 wherein said first unit is
provided with a concave groove in a circular periphery thereof, and
said rod extends lengthwise of said first unit in said groove, said
groove having a curvature substantially equal to the curvature of
said second unit, said groove being thereby configured to receive
said second unit as said second unit is drawn axially into said
groove by said rod to be placed in said position alongside said
first unit.
10. The device in accordance with claim 9 wherein said first unit
is provided with a notch extending from said groove, and said
second unit is provided with a detent configured to be snugly
received by said notch when said second unit is in said position
alongside said first unit to prevent rotative movement of said
second unit in said position.
11. The device in accordance with claim 10 wherein said detent
extends from an end of said second unit and is adapted to extend
into said groove of said first unit and serves as a stop member to
limit rotative movement of said second unit relative to said first
unit.
12. The device in accordance with claim 10 wherein said base
portion includes a handle component.
13. An observation device comprising:
a shaft having a proximal and a distal end;
first and second discrete observation units, with said first
observation unit fixed to said distal end of said shaft in
alignment with said shaft;
a rod having a proximal end and a distal end, said rod extending
lengthwise through said shaft and through a portion of said first
unit, said rod being off-set from an axis of said shaft and being
fixed at said distal end thereof to said second unit at a location
offset from the center axis of said second unit; and
operating means for moving said second unit between a first
position in which it is aligned end-to-end with said first unit and
a second position in which said second unit is disposed alongside
of and parallel to said first unit, said operating means comprising
means for sequentially effecting (a) rotational movement of said
rod in a first rotational direction to effect rotational movement
of said second unit relative to said first unit, and (b) axial
movement of said rod to effect axial movement of said second unit
in a first axial direction relative to said first unit, said
operating means also being adapted to move said second unit from
said second position back to said first position by sequentially
effecting (a) axial movement of said rod to effect axial movement
of said second unit in a second axial direction relative to said
first unit and (b) rotational movement of said rod in a second
rotational direction to effect rotational movement of said second
unit relative to said first unit.
14. The device in accordance with claim 13 further including a base
portion and wherein said operating means comprises an extension of
said rod having an externally threaded portion and an external
conically shaped surface, a drive gear, means attached to said base
portion for rotatably supporting said drive gear, a yoke fixed to
said base portion, an internally threaded nut mounted on and
connected to said externally threaded portion by a screw
connection, said nut having a first gear portion engaged with said
drive gear, a second holding portion engaged with said yoke whereby
said nut is restrained against axial movement by said while
remaining free to rotate on said externally threaded portion of
said rod extension, and a third conical portion which is adapted to
engage said external conically shaped surface of said rod extension
whereby to rotative movement of said nut relative to said rod
extension and thereby terminate axial movement of said rod
extension by relative rotation of said rod extension and said
nut.
15. The device in accordance with claim 14 further including
manually operable means for effecting rotation of said drive
gear.
16. The device in accordance with claim 14 further including a
bidirectional electrical motor coupled to said drive gear for
effecting rotation of said drive gear and thereby effecting
rotational and axial movement of said rod extension and said
rod.
17. The device in accordance with claim 13 wherein said first unit
is provided with a concave groove in a circular periphery thereof,
and said rod extends lengthwise of said first unit in said groove,
said groove having a curvature substantially equal to the curvature
of said second unit, said groove being thereby configured to
receive said second unit as said second unit is drawn axially into
said groove by said rod to be placed in said position alongside
said first unit.
18. The device in accordance with claim 14 wherein said base
portion includes a handle component.
19. The device in accordance with claim 13 wherein said first unit
is provided with a notch extending from said groove, and said
second unit is provided with a detent configured to be snugly
received by said notch when said second unit is in said position
alongside said first unit to prevent rotative movement of said
second unit in said position.
20. The device in accordance with claim 19 wherein said detent
extends from an end of said second unit and is adapted to extend
into said groove of said first unit and serves as a stop member to
limit rotative movement of said second unit relative to said first
unit.
21. The device in accordance with claim 13 wherein said device
comprises an endoscope and at least one of said first and second
units comprises an electronic optical image sensor.
22. A device for carrying first and second units in tandem and
moving the second of said units to a position abreast of the first
of said units, said device comprising:
first and second units;
a base portion, said first unit being fixed to said base
portion;
a rod extending through said first unit removed from an axis of
said first unit and connected to said second unit at a point
removed from an axis of said second unit,
said rod being fixed to a screw member having a threaded portion
and a non-threaded portion;
said non-threaded portion of said screw member being disposed in a
bore in a frame member mounted on said base portion, and having a
conical portion proximate said screw member threaded portion;
a nut threadably mounted on said screw member and having a rotary
gear portion, and internal conical portion complementary to and in
alignment with said non-threaded screw conical portion, and a
holding portion by which said nut is retained by a yoke fixed to
said base portion, said nut being limited by said yoke to only
rotational movement;
a rotary drive gear mounted on said base portion and threadedly
engaged with said nut rotary gear portion; and
an actuator mounted on said base portion and connected to said
rotary drive gear for effecting rotation of said rotary drive
gear;
whereby upon rotation of said actuator, said rotary drive gear
turns said nut, said conical portion of said nut being frictionally
engaged with said conical surface of said screw member, such that
turning said nut causes turning of said screw member, to cause
turning of said rod to move said second unit transversely to said
first unit to a position out of alignment with said first unit, and
whereby upon said second unit reaching the end of its transverse
movement, rotation of said screw member is stopped and continued
turning of said rotary drive gear causes continued turning of said
nut rotary gear portion to move said screw member axially, thereby
to move said rod axially, to move said second unit axially to said
position abreast of said first unit; and to move said screw member
conical surface away from said nut conical portion; and
whereby upon counter rotation of said actuator and said rotary
drive gear, said nut gear portion turns and moves said screw member
and said rod and said second unit axially until a rearward surface
of said second unit clears a forward surface of said first unit
substantially at which time said screw member conical surface
engages said nut conical portion to prevent further axial movement
of said screw member in said nut, and to frictionally fix said
screw member to said nut, and further rotation of said nut causes
rotation of said screw member and said rod, to return said second
unit to said position in tandem with said first unit.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to mechanical devices for carrying a
plurality of units in a first disposition and moving at least one
of the units to a second disposition relative to at least one other
of the units, and is directed more particularly to a device for
supporting and carrying two units end-to-end and for moving one of
the units alongside the other of the units.
2. Description of the Prior Art
There are instances in which it is desired to mount and carry units
in tandem for passing the units through as small an orifice as
possible in a boundary layer and then rearranging the units in a
side-by-side relationship.
In the field of medical instruments, for example, it is beneficial
in endoscopic examination and surgery to introduce two or more
units serially through a relatively small orifice and, once inside
the body, reposition the units side-by-side, a disposition of units
which, if inserted initially, would require an orifice twice as
large, or more, than the small orifice required for introduction of
the units in tandem.
In endoscopes, it is known to provide an electronic optical image
sensor (hereinafter also referred to as a video device or camera)
at the distal end of the endoscope shaft. Such video devices are
shown and described in the following U.S. Pat. Nos. 4,832,003,
issued May 23, 1989, in the name of Hisao Yabe; 5,021,888, issued
Jun. 4, 1991, in the name of Yuu Kondau, et al; 5,166,787, issued
Nov. 24, 1992, in the name of Keaus Ission; 5,662,584, issued Sep.
2, 1997 in the name of Koichiro Hori et al., and 5,538,497, issued
Jul. 23, 1996 in the name of Koichiro Hori. In the field of
endoscopes, it would be beneficial to provide an endoscope shaft
with two or more electronic optical image sensors which could be
introduced into the body serially and, once inside the body,
rearranged to side-by-side positions, such that two or more images
could be transmitted to provide to an operator a stereoscopic view
of the body portion under examination.
In surgery, it is desirable to limit the size of an incision
required for introduction of surgical tools and for viewing of the
area of concern. It would be beneficial to have available an
instrument by which two units could be introduced serially through
an orifice of limited size, with one of the units carrying the
required tool and the other unit movable to a position alongside
the first unit and carrying image sensing means for providing a
view of the tool in operation.
Such an instrument could prove beneficial in any application or
area of use wherein it is desired to limit the size of an orifice
through a boundary layer, to pass two or more units through the
orifice and, thereafter, to position the units side-by-side. Thus,
for example, it is desired and often necessary to severely limit
the size of any orifice in the pressure hull of deep underwater
vehicles. It is also desirable to use acoustics sensors on such
vehicles for determining range, with at least two sensors being
required for purposes of triangulation and thereby determination of
range. It is recognized that a device adapted to pass acoustic
sensors through a pressure hull serially and thereafter position
the sensors side-by-side would be beneficial in underwater
detection and tracking assemblies.
SUMMARY OF THE INVENTION
An object of the invention is to provide a novel device for
supporting and carrying two units end-to-end such that the units
may be passed through a relatively small orifice in a boundary
layer and, thereafter, positioned side-by-side.
A further object of the invention is to provide such a device
having novel means for rotatively moving one of the two units out
of axial alignment with the other of the units and, thereafter,
axially moving the one unit relative the other unit.
A still further object of the invention is to provide an endoscope
for supporting and carrying two units, at least one of which is an
electronic optical image sensor, end-to-end such that the units may
be passed through a relatively small orifice in a mammal body and,
thereafter, for positioning the units side-by-side.
A still further object of the invention is to provide a novel drive
assembly for imparting rotative and axial movement to a rod affixed
to one of the aforementioned units, whereby to effect rotational
and axial movement of one unit relative to the other of the
units.
With the above and other objects in view, as will hereinafter
appear, a feature of the present invention is the provision of a
device for carrying first and second units in aligned end-to-end
disposition at the distal end of a shaft and for moving one of the
units into position alongside the other of the units. The device
comprises a base portion to which a proximal end of the shaft is
fixed. A first unit of the two is fixed to the distal end of the
shaft and is in alignment with the shaft. A rod extends lengthwise
through the shaft and through or alongside of a portion of the
first unit, the rod being off-set from the center axis of the shaft
and being fixed at a distal end thereof to the second unit at a
location removed from an axis of the second unit. A drive shaft is
fixed to the rod at a proximal end of the rod, the drive shaft
having a threaded portion and a non-threaded portion. The device
further comprises actuator or operating means mounted on the base
portion for (1) effecting rotational movement of the drive shaft
and thereby rotational movement of the rod, with a consequent
rotational movement of the second unit to a position removed from
alignment with the first unit, and (2) effecting axial movement of
the drive shaft and rod so as to effect axial movement of the
second unit into position alongside the first unit.
In accordance with a further feature of the invention the device
described herein above is an endoscope and at least one of the
units comprises an electronic imaging sensor or video device.
The above and other features of the invention, including various
novel details of construction and combinations of parts, will now
be more particularly described with reference to the accompanying
drawings and pointed out in the claims. It will be understood that
the particular devices embodying the invention are shown by way of
illustration only and not as limitations of the invention. The
principles and features of this invention may be employed in
various and numerous embodiments without departing from the scope
of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference is made to the accompanying drawings in which are shown
illustrative embodiments of the invention, from which its novel
features and advantages will be apparent.
In the drawings:
FIG. 1 is a perspective view of a pair of units mounted on a distal
end of a shaft;
FIG. 2 is similar to FIG. 1, but shows one of the units moved
rotatively out of alignment with the other of the units;
FIG. 3 is similar to FIG. 2, but shows the one unit moved axially
to a position alongside the other unit;
FIG. 4 is a top plan view, with portions broken away, of a base
portion of the device;
FIG. 5 is an end elevational view of the device of FIG. 4;
FIG. 6 is a fragmentary cross-sectional view taken along line 6--6
of FIG. 4;
FIG. 7 is a side elevational view of the base portion of the device
of FIG. 4;
FIGS. 8 and 9 are longitudinal sectional view of portions of a gear
nut, yoke and drive shaft shown in different relative operating
positions; and
FIG. 10 is a view similar to FIG. 1 of an alternative embodiment of
the device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, it will be seen that in an illustrative
embodiment of the invention there are provided first and second
units 10, 12 mounted on a distal end 14 of a hollow shaft 16. The
first unit 10 is fixed to the shaft 16 in end-to-end relationship,
and is of the same outer configuration and size as the shaft 16,
typically cylindrical. The second unit 12 is adapted to be
positioned in alignment with the first unit 10 as shown in FIG. 1,
and is further adapted to be moved transversely of the first unit
10 (FIG. 2) and axially of the first unit 10 (FIG. 3), as will be
further described hereinbelow. The second unit 12, at least at its
proximal end 18, preferably is of the same outer configuration and
size as the first unit 10, such that the assembly of shaft 16,
first unit 10, and second unit 12, in aligned relationship, as
illustrated in FIG. 1, may be passed through a boundary layer, such
as the skin of a mammal body or a vehicle subject to unusually
harsh environments, requiring as small an orifice as possible.
In a preferred embodiment, the device illustrated in part in FIG. 1
comprises an endoscope in which the units 10, 12 are electronic
imaging units, or capsules containing electronic imaging units. In
such instances, electronic and fiber-optic leads, shown
collectively at 20, may extend through the shaft 16 to the first
unit 10 for the purpose of providing electrical connections to the
electronic components of that imaging unit and transmitting light
for illuminating the scene or site being viewed by the optical
components of the imaging unit.
As used herein, the term "electronic imaging unit" comprises an
electronic optical image sensor such as a CCD module and also one
or more optical components for generating an optical image of the
area under inspection and focusing that image onto the image
sensor. Such a unit, also known in the art as a video camera or
video device, may also comprise additional components for operating
the image sensor and generating an electrical video output signal
representative of the scene or site being inspected. By way of
example but not limitation, for the purposes of this invention the
electronic imaging units may be like the ones disclosed and
illustrated by said U.S. Pat. Nos. 4,832,003, 5,021,888, 5,166,787,
5,662,584 and 5,538,497. The fiber optic leads may take the form of
optical fibers or rods arranged in unit 10 for optimum transmission
of light to illuminate the scene or site being inspected.
A stiff rod 22 extends through the shaft 16 and a bore 36 in first
unit 10, and has its distal end 24 connected to the proximal end 18
of the second unit 12. Rod 22 extends parallel but eccentric to the
longitudinal axis of shaft 16. Rod 22 is slidable lengthwise and is
also rotatable on its own axis relative to shaft 16 and first unit
10. When the units 10, 12 comprise optical image sensors, or other
electronic or electrical devices, or means for illuminating the
scene or site under inspection, the rod 22 may be a tubular member
having disposed therein additional electronic and/or fiber-optic
leads, identified collectively by the numeral 26, that are
connected to the second unit.
Referring to FIG. 2, it will be seen that rotation of the rod 22 on
its axis causes corresponding rotative movement of the second unit
12 from the position shown in FIG. 1 to the position shown in FIG.
2. As noted above, the rod 22 is off-set from the axis of the shaft
16. Also rod 22 is joined to the second unit 12 at a location
off-set from the axis of the second unit. Accordingly, rotation of
the rod 22 causes lateral translational movement of the second unit
12 to a position no longer aligned with the first unit 10, as
illustrated in FIG. 2.
The first unit 10 is provided with a groove 28 having a concave
configuration complementary to the rounded configuration of the
second unit 12, e.g., groove 28 has a circular curvature
complementary to the circular curvature of the cylindrical outer
surface of unit 12. The second unit 12 is provided with a detent 30
extending from the proximal end 18 of the second unit. Detent 30
extends parallel but is spaced radially from the center axis of
second unit 12. When the second unit 12 is aligned with the first
unit 10 (FIG. 1), the detent 30 extends into groove 28 and is
engaged with a longitudinally-extending wall portion 32 of groove
28. On rotative movement of the second unit 12 (counterclockwise as
seen in FIG. 1), the unit rotates until the detent 30 engages an
opposite wall portion 34 of groove 28 (FIG. 2). Thus, the detent 30
serves as a stop member, stopping rotative movement of the second
unit 12 in its fully aligned position (FIG. 1) and in its
transversely fully extended position (FIG. 2).
As noted previously, rod 22 is movable axially and rotatable on its
own axis in shaft 16 and bore 36 of the first unit 10. Accordingly,
once the second unit 12 has been rotated to the position
illustrated in FIG. 2, it may then be moved axially in a proximal
direction (leftwardly, as viewed in FIG. 2) into and along the
groove 28 to a proximal limit position shown in FIG. 3, wherein the
proximal end 18 of the second unit 12 abuts a proximal end wall 38
of the groove 28. As the second unit's proximal end 18 approaches
the groove end wall 38, the detent 30 enters a substantially
complementary-shaped notch 40 in unit 10. When the unit 12 is in
such position, the opposite edges of groove 28 lock the unit
against rotation in either direction on the axis of rod 22. In this
preferred embodiment, units 10, 12 are provided, respectively, with
distal end faces 42, 44 (FIG. 3). Consequently, when the units 10,
12 are side-by-side as shown in FIG. 3, the faces 42, 44 lie in a
common plane that intersects the longitudinal axis of shaft 16 at a
right angle.
In a an contemplated embodiment in the form of an endoscope wherein
both units 10, 12 are electronic optical imaging units,
side-by-side positioning of the two imaging units provides
stereoscopic viewing of an internal region of a mammal body. In a
further contemplated embodiment wherein the units 10, 12 are
acoustic sensing devices, such side-by-side positioning of the
units provides for sound ranging determination by triangulation. It
will be appreciated that for some applications it may be preferable
for the units 10, 12 not to have their distal faces in a co-planar
relationship, as, for example, where one unit is used to illuminate
and/or observe surgical work or the like that is being done by
means carried by or inserted through the other unit, in which case
it may be preferable to have the illuminating and/or observing unit
off-set rearwardly from the other unit.
Referring to FIG. 4-7, it will be seen that the illustrated
instrument or device includes a base portion 50 to which a proximal
end 46 of the shaft 16 is fixed. The base 50 may be shaped and
sized to function as a handle whereby the device may be grasped and
manipulated. The base portion 50 includes a base plate 52 to which
is bolted a shaft mount 54 in which the proximal end of shaft 16 is
rigidly secured. Also mounted to base portion 50 is an operating
mechanism assembly or actuator assembly hereinafter described for
imparting rotative and axial movement to the rod 22.
The operating mechanism assembly comprises a drive shaft 62 that is
connected by a coupling member 64 to the proximal end of rod 22.
Shaft 62 comprises an externally threaded section 66 and a larger
diameter unthreaded section 68. In the illustrated embodiment, the
external screw thread on shaft section 66 is formed as a left hand
thread. The distal or forward end of shaft portion 68 has a
conically-shaped surface 70 that extends to the threaded section
66. The proximal portion 68 of shaft 62 is rotatably mounted in a
vertical extension 74 of base plate 52. The latter has a bore 75
that is sized so as to make a close fit with shaft portion 68 such
that the shaft is restrained against lateral movement while being
free to slide axially and also to rotate on its own axis relative
to the shaft mount portion 74.
Rotatably mounted on the threaded portion 66 of shaft 62 is a gear
nut 76. As seen in FIGS. 4, 8 and 9, gear nut 76 comprises a rear
(proximal) portion 78 and a forward beveled gear portion 80 (FIGS.
8 and 9). The gear portion 80 is characterized by a circumferential
array of gear teeth 82. Between the proximal portion 78 and the
distal portion 80 of nut 76 is a groove 84. The latter is sized to
make a close fitting connection with a yoke 88 that is attached to
and extends vertically from base plate 52. The yoke functions to
limit axial movement of nut 76 while allowing it to rotate. The
internal surface of nut 76 is threaded with a left hand thread so
as to mate with the external left hand threads on shaft 66.
Additionally, at its proximal end the nut has a conical counterbore
90. The latter is sized so as to be able to make a tight contact
with the conical outer surface 70 formed at the distal end of the
rear portion 68 of shaft 62. Referring to FIGS. 8 and 9, it is
preferred, but not essential, that the external threads on shaft 62
terminate short of the conical surface 70, leaving a portion 94 of
shaft 62 unthreaded. The angle of the counterbore surface 90 is the
same as the angle of the conical surface 70 on shaft 62, so that
the two surfaces may make full engagement with one another when the
nut shaft is rotated to bring its conical counterpart surface 90
into engagement with the conical shaft surface 70. When the two
conical surfaces on shaft 62 and gear nut 76 are brought together
they will tend to stick to one another due to friction, producing a
self-locking action. This locking action can be enhanced by
appropriately selecting the angles of the conical surfaces and the
materials of which the shaft and gear nut are made (preferably
steel), and by regulating the smoothness of the machined conical
surfaces and the pitch of the screw threads. However, the two
conical surfaces can be separated by applying a turning torque to
the gear nut that is sufficient to break the frictional bond
between surfaces 70 and 90.
The gear nut 76 and shaft 62, and specifically their conical
surfaces 90 and 70 respectively, combine to form a friction clutch
mechanism, the operation of which is described hereinafter.
Referring to FIGS. 4, 5 and 7, the base plate 52 has two
vertically-extending rectangular posts or stanchions 100 and 102
that have circularly-shaped grooves 104 in their upper end
surfaces. The groove 104 in post 100 serves as nesting place for a
manually operable shaft 106 that has a large thumb wheel 108 at its
outer end. The inner end of shaft 106 carries a bevel gear 110. The
groove 104 in the other post 102 supports an electric motor 112
having another bevel gear 114 mounted on the end of its output
shaft 116. Shaft 106 is rotatably held in place on post 100 by a
clamp member 118 which is held in place by screw bolts 120.
Similarly motor 112 is held in place on post 102 by another clamp
member 118 which is held in place by additional screw bolts 120.
The gears 110 and 114 are designed and positioned to mesh with gear
82. Shaft 106 is rotatable bidirectionally by hand, and motor 112
is a reversible motor so as to permit bidirectional rotation of its
gear 114.
Motor 112 is adapted to be connected to a suitable power supply
P.S. via switch means 124. The switch means are arranged and
adapted to selectively energize the motor in a forward or reverse
direction. The motor may be an a.c. motor or a d.c. motor. In the
latter case the power supply may be a battery. It also is
contemplated that a pneumatic or hydraulic motor may be used in
place of an electric motor.
It should be noted that motor 112 and gear 14 may be omitted, in
which case the device may be operated by rotating shaft 106 via
thumb wheel 108. Alternatively shaft 106 may be omitted and the
device operated by way of motor 112. If it is desired to have both
operating means present, it is necessary to use a motor 112 whose
operating shaft 116 is substantially free-wheeling when the motor
is deenergized, so as keep low the amount of torque required to
rotate shaft 106.
Operation of the foregoing apparatus will now be described, with
movement of shaft 62 being affected by operation of motor 112.
Assume that units 10 and 12, are aligned end-to-end (FIG. 1) for
penetrating a boundary, via an aperture that is just large enough,
or expandable enough, to permit entry of unit 12. By way of
explanation, the boundary may be human tissue and the aperture may
be an incision in that tissue 6. When the units 10, 12 are in this
position, the gear nut's internal conical surface 90 is engaged
with and frictionally locked to the external conical surface 70 of
shaft 62. Motor 112 is energized in a forward direction, causing
its gear 114 to turn gear nut 76 in a counter-clockwise direction
as viewed in FIG. 6. However, gear nut 76 is frictionally locked
tight on shaft 62 by virtue of being engaged with conical surface
70. Since unit 12 is not locked against rotation, gear nut 76 will
not rotate on shaft 62, but instead gear nut 76 and shaft 62 will
both rotate together, causing transverse movement of the second
unit from the position shown in FIG. 1 to the position shown in
FIG. 2. As described above, the second unit 12 is stopped in its
transverse movement by engagement of the detent 30 with the groove
wall portion 34. As a result, rod 22 and shaft 62 are thereupon
prevented from further rotation. Further as a result, if motor 112
remains energized and continues to drive gear nut 76 in the same
direction, the gear nut will break its frictional bond with the
shaft's conical surface 70 and continue to rotate under the driving
force exerted by the motor. This continued rotation of the gear nut
76 on shaft 62 causes the latter to move axially and rearwardly in
support 72 until the second unit 12 is drawn alongside the first
unit (FIG. 3), at which point the motor 112 will tend to stall and
may be shut off automatically by a current-sensing limit switch
(not shown), or manually by the surgeon, to avoid motor
overheating.
When it is desired to return the second unit 12 to a position in
line with the first unit 10, the motor 112 is activated in a
reverse direction, rotating the gear nut 76 in a clockwise
duration. This reverse rotation of gear nut 76 causes shaft 62 to
move axially from the position shown in FIG. 3 to the position
shown in FIG. 2. At substantially the same time as the second unit
proximal end 18 clears the first unit 10, the internal conical
surface 90 of the gear nut engages conical surface 70 of shaft 62,
stopping axial movement of the screw shaft and locking the gear nut
to the shaft by virtue of a frictional bond being established
between the mutually engaged surfaces 70 and 90. As a result,
further rotation of the gear nut in the same clockwise direction
causes the second unit 12 to rotate from the position shown in FIG.
2 to the position shown in FIG. 1, at which time the motor 112 will
tend to stall and may be shut off automatically by the same or a
different current-sensing limit switch, or manually by the surgeon,
to avoid motor overheating.
The operation of the device by grasping and rotating thumb wheel
108 is substantially identical to the above-described operation of
the device using motor 112. When both operating mechanisms are
present, the manual one serves as a back-up for the motorized
one.
Although not shown, it is contemplated that a cover member may be
provided for attachment to base plate 52, with the cover member
being shaped so as to conceal the operating mechanism without
interfering with its performance. That cover member and base
portion 50 would form a housing that also serves as a handle by
which the entire unit may be held.
Referring now to FIG. 10, it is contemplated that instead of being
a discrete unit affixed to the shaft 16, as described above, the
unit 10 may comprise a hollow end portion 10A of the shaft 16. In
the latter case, the first unit contained by the end portion 10a
may be a discrete video unit comprising an electronic image sensor,
an optical system (comprising at least an objective lens) for
focusing an image of a scene or site being viewed onto the image
sensor, and illuminating means for illuminating the scene or site.
Alternatively, the end portion 10A may serve simply as a conduit
for introducing a surgical instrument to the surgical site, while
the video unit 12 serves as a means for observing the surgical
site. It also is contemplated that the end portion 10A may serve as
a housing for an electronic acoustic energy-sensing unit.
It is to be understood that the present invention is by no means
limited to the particular construction or modification herein
disclosed and/or shown in the drawings, but may comprise other
modifications or equivalents within the scope of the claims. For
example, for some applications, the outer configuration and size of
the first unit 10 may be different than that of shaft 16, and the
second unit 12 need not have the same size and configuration as
first unit 10 or shaft 16. It also is contemplated that shaft 16
and rod 22 may be flexible instead of rigid or stiff. The manually
operated shaft 106 may be modified so as to be driven by a second
motor. Another contemplated modification is to mount the motor 112
so that its output shaft 116 extends parallel rather than at a
right angle to drive shaft 62, and then appropriately modify the
gearing that couples motor shaft 116 to gear portion 80 of nut 66.
A further possible modification is to use gears that are not
beveled. It also is contemplated to modify the gear teeth on nut 76
so as to permit using a sprocket and timing belt arrangement for
coupling motor shaft 116 and/or shaft 106 to that nut. Also instead
of having the gear teeth 82 on nut 76, a portion of the exterior of
the nut could be shaped so as to function as a friction roller, and
the shafts 106 and 116 could be fitted with friction rollers in
place of gears, with the friction rollers on shafts 106 and 116
engaging the corresponding portion on the nut to effect rotation of
the nut. Another possible modification is to replace the specific
form of friction clutch mechanism shown in the drawings with a
different form of clutch mechanism.
Still other modifications will be obvious to persons skilled in the
art.
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